Fuel for internal combustion engines



United States Patent 3,294,500 FUEL FOR INTERNAL CGMBUSTION ENGINES Max Zimmermann, Leverkusen, Werner Miiller, Cologne, and Walter Hagge, Leverkusen, Germany, assignors to Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a German corporation No Drawing. Filed Jan. 25, 1962, Ser. No. 168,801 Claims priority, application Germany, May 15, 1954, F 14,727 Claims. (Cl. 44-70) v This application is a continuation-in-part application of application Serial Number 508,295, filed May 13, 1955, now abandoned.

The present invention refers to a new composition of matter; more particularly, it concerns a new composition which contains a fuel for combustion engines and mixtures of neutral esters of polycarboxylic and of phosphonic acids.

It has been found, that such mixtures have valuable properties: as additives to fuels used in combustion engines, such as carburetor fuel or diesel fuel, they are capable of protecting the exposed engine parts against corrosion and incrustation so that the engine'parts, particularly pistons, rings, grooves and the like do not prematurely wear out.

The acids on which the esters of the polycarboxylic or phosphonic acids may be based are, for example, phthalic acid, isop-hthalic acid, terephthalic acid, trimellitic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid and the halogen substitution products of these acids; hexahydrophthalic acid, alkylnaphthalene dicarboxylic acids; adipic acid, pimel-ic acid, suberic acid, azelaic acid, sebacic acid, nonane dicarboxylic acid, decane dicarboxylic acid or pheny-lphos-p honic acid, its halogen and alkyl substitution products, such as for example di(chlorophenyl)phosphonic acid, di(fiuorophenyl)phosphonic acid, tolyl phosphonic acids, xylyl phosphonic acids, di(tolyl)phosp-honic acids, (ethylphenyl) phosphonic acid, naphthyl phosphonic acid, alkylna-phthyl phopshonic acids, cyclohexyl phosphonic acid, dodecyl phosphonic acid, as well as phos'pihonic acids which are substituted by radicals of petroleum fractions.

The alcohols on which the esters are based may be the following, for example: metyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, nonyl, or decyl alcohols etc., stearyl alcohol, and cycl-ohexanol.

Thus, the neutral phosphonic esters correspond to the general formula wherein R stands for alkyl or cycloalkyl, X represents alkyl, cycloalkyl, aryl, alkaryl, or halogen-substituted aryl, while Y stands for one of the aforesaid OR-radicals or X radicals.

The ester components are suitably chosen so that the boiling point of the esters is sufficiently high as to enable the ester mixtures to be used for the desired purpose without any risk of a substantial loss by evaporation or the like.

When using the mixtures according to the invention in fuels for combustion engines, it is irrelevant whether the components are added to the fuels together or separately. In order to render the measuring more easy, it is also possible to dissolve the esters or their mixtures first in a mineral oil, preferably a spindle oil of low viscosity from naphthenes, and to admix this concentrate with the fuels. The amounts of the ester mixture required vary within wide limits and can easily be ascertained by preliminary tests. They frequently depend on the nature of the fuels and the additives which may already be present in the fuels. In general, 1-2 parts by weight of the mixture according to the invention are sufiicient per 1000 to 100,000 parts by weight of fuel. The ratio of the esters of carboxylic acid to phosphon-ic acid can also be varied Within Wide limits. A suitable ratio of the mixture is about 5 parts by weight of carboxyl-ic ester to 1 part by weight of phosphonic ester. Instead of individual esters there can also be applied mixtures of different esters of carboxylic acid or phosp honic acid.

If desired, basic compounds, particularly amines, can be added to the fuels apart from the mixtures of the invention.

Example 1 To 100 kg. of a normal carburetor fuel of a mixutrc of equal parts of top benzine and cracked benzine there is added a mixture of 0.005 kilogram of di(chlorophenyl)phosphonic acid-n-butyl ester, 0.025 kilogram of dibutyl phthalate and 0.170 kilogram of a mineral oil of low viscosity, a so-called spindle oil having a viscosity of about 1.5 Engler degrees at 50 C. This fuel inhibits incrustation and corrosion of the engine parts in normal LC. engines.

A mixture containing instead of di(chlorophenyl)phosphonic acid-n-butyl ester the same amount of di(fluorop henyl)phosphonic acid-n-butyl ester shows the same good results.

Example 2 To 100 kilograms of a carburetor fuel comprising about two-thirds of top benzine and one-third of cracked benzine and 0.04 percent by volume of tetraethyl lead is added 0.01 kilogram of a mixture of parts by weight of di(chlorophenyl)iphosphonic acid-n-butyl ester and 20 parts by weight of chlorophenyl phosphonic acid dibutyl ester, 0.05 kilogram of methyl-amyl ester of adipic acid and 0.12 kilogram of a gas oil.

This mixture particularly prevents the motor parts in two-stroke engines becoming encrusted or corroded. The same result is obtained by replacing the adipic acid ester by the imethyl-butyl ester of terephthalic acid as a component of the mixture.

Example 3 A fuel for combustion engines is prepared by adding to 2500 kilograms of a normal carburetor fuel kilograms of'a so-called two-stroke oil mixed with 0.05 kilogram of chloro'phenyl phosphonic acid distearyl ester, 0.20 kilogram of di-buty l ester of sebacic acid and 0.05 kilogram of dicyclohexyl amine. By the use of this fuel many defects are cured which occur with fuels containing no ester mixtures.

Example 4 .additive mixture, said mixture consisting essentially of (1) a neutral ester of an acid selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, diphenyl dicarboxylic acid and corresponding halodi-phenyl dicarboxylic acids, hexahydrophthalic acid, alkylnaphthalene dicarboxylic acid, adipic acid, pimelic acid, suberic acid, azclaic acid,sebacic acid,nouane dicarboxylic acid, decane dicarboxylic acid, the corresponding halo and alkyl hydrocarbon substitution products thereof with members selected from the group consisting of an alkanol and cycloalkanol, and (2) a neutral phosphonic acid ester of the formula wherein R is a member selected from the group consisting of alkyl and cycloalkyl; X is a member selected from the group consisting of alkyl, cycloalkyl, aryl, alkylaryl, and haloaryl; Y is a member selected from the group consisting of alkoxy, cycloalkoxy and X, as above defined; the ratio of additive mixture to fuel being about 1-2:1000100,000.

2. The composition of claim 1 wherein the alcohol reactants of 1) are members selected from the group consisting of methyl, ethyl, propyl, 'butyl, amyl, hexyl, heptyl, octyl, nonyl, decyl, stearyl, and cyclohexyl alcohols.

3. The composition of claim 4 in which the phosphonic acid ester is a chlorophenyl phosphonic acid ester.

4. A composition according to claim 1 wherein the ratio of component (1) to component (2) of the additive mixture is about 4-20:1 in parts by weight.

5. A fuel for combustion engines according to claim 1 wherein the ratio of component (1) to component (2) is about 4-8.5:1 parts by weight.

6. A fuel for internal combustion engines comprising a fuel base of a mixture of distillate benzine and cracked benzine containing an additive mixture of di(chlorphenyl) phosphonic aicid-n-butyl ester and dibutyl phthalate, with a mineral oil, the ratio of additive mixture to fuel base being about 3:10,000 in parts by weight, and the ratio of dibutyl phthalate to di(chlorphenyl)phosphonic acid-n-butyl ester being about 5:1 in parts by weight.

7. A fuel for internal combustion engines comprising a fuel base of distillate benzine and cracked benzine and an additive mixture of di(fluorophenyl) phosphonic acidn-butyl ester and dibutyl phthalate with a mineral oil, the ratio of additive mixture to fuel base being about 3: 10,000 parts by weight and the ratio of dibutyl phthalate to di(fiuorophenyl) phosphonic acid-n-butyl ester is about 5:1 parts by Weight.

8. A fuel for internal combustion engines comprising a liquid fuel for an internal combustion engine consisting of distillate benzine and crack benzine and an additive mixture of di(ehlorophenyl) phosphonic acid-n-butyl ester, chlorophenyl phosphonic acid dibutyl ester and the methyl-amyl ester of adipic acid in the presence of tetraethyl lead and a gas oil, the ratio of said additive mixture to said liquid fuel being about 1:10,000 parts by weight and the ratio of adipic acid ester to the phosphonic acid ester being about 5:1 parts by weight.

9. A fuel for internal combustion engines comprising a fuel base of distillate benzine and cracked benzine and an additive mixture of di(chlorophenyl) phosphonic acidn-butyl ester, ch'lorophenyl phosphonic acid dibutyl ester and the methyl-butyl ester of terephthalic acid in the presence of tetraethyl lead and a gas oil, the ratio of said additive mixture to fuel component being about 1110,000 parts by weight and the ratio of terephthalic acid ester t0 the phosphonic acid esters is about 5: 1.

10. An additive mixture for fuel selected from the group consisting of carburetor fuel and diesel fuel consisting of (A) a neutral ester of a polycarboxylic acid and an alcohol selected from the group consisting of alkanol and a cycloalkanol and (B) a neutral phosphonic acid ester of the formula C|)R 0=1lX Y wherein the ratio of (A) and (B) is about 4-2021 in parts by Weight, and, wherein R stands for a member selected from the group consisting of alkyl and cycloalkyl; X is a member selected from the group consisting of alkyl, cycloa-lkyl, aryl, alkylaryl and halogensubstituted aryl; and Y 'is a member selected from the group consisting of X, --O-alkyl, and O-cyeloalkyl.

References Cited by the Examiner UNITED STATES PATENTS 2,174,019 9/1939 Sullivan 25249.8 2,204,598 6/1940 Humphreys et al. 252396 2,215,590 9/1940 Maverick 25257 2,481,372 9/1949 Von Fuchs et a1 252498 2,485,341 10/1949 Wasson et al. 252-49.8 2,573,568 10/1951 Harman et a1 25246.7 2,843,466 7/1958 Greenwald 4470 2,897,071 7/1959 Gilbert 44-69 FOREIGN PATENTS 5/1959 Canada. 5/1954 Great Britain. 

1. A COMPOSITION OF MATTER CONTAINING A LIQUID FUEL FOR INTERNAL COMBUSTION ENGINES AND AN ACTIVE AMOUNT OF ADDITIVE MIXTURE, SAID MIXTURE CONSISTING ESSENTIALLY OF (1) A NEUTRAL ESTER OF AN ACID SELECTED FROM THE GROUP CONSISTING OF PHTHALIC ACID, ISOPHTHALIC ACID, TEREPHTHALIC ACID, DIPHENYL DICARBOXYLIC ACID AND CORRESPONDING HALODIPHENYL DICARBOXYLIC ACIDS, HEXAHYDROPHTHALIC ACID, ALKYLNAPHTHALENE DICARBOXYLIC ACID, ADIPHIC ACID, PIMELIC ACID, SUBERIC ACID, AZELAIC ACID, SEBACIC ACID, NONE DICARBOXYLIC ACID, DECANE DICARBOXYLIC ACID, THE CORRESPONDING HALO AND ALKYL HYDROCARBON SUBSTITUTION PRODUCTS THEREOF WITH MEMBERS SELECTED FROM THE GROUP CONSISTING OF AN ALKANOL AND CYCLOALKANOL, AND (2) A NEUTRAL PHOSPHONIC ACID ESTER OF THE FORMULA 